From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi0-f70.google.com (mail-oi0-f70.google.com [209.85.218.70]) by kanga.kvack.org (Postfix) with ESMTP id D4DA1440417 for ; Wed, 8 Nov 2017 10:21:47 -0500 (EST) Received: by mail-oi0-f70.google.com with SMTP id r128so2315627oig.3 for ; Wed, 08 Nov 2017 07:21:47 -0800 (PST) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id n89si2158311otn.406.2017.11.08.07.21.46 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 08 Nov 2017 07:21:46 -0800 (PST) Date: Wed, 8 Nov 2017 10:21:38 -0500 (EST) From: Mikulas Patocka Subject: Re: [PATCH] vmalloc: introduce vmap_pfn for persistent memory In-Reply-To: <20171108150447.GA10374@infradead.org> Message-ID: References: <20171108095909.GA7390@infradead.org> <20171108150447.GA10374@infradead.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Christoph Hellwig Cc: Ross Zwisler , linux-mm@kvack.org, linux-nvdimm@lists.01.org, Dan Williams , dm-devel@redhat.com, Laura Abbott , Christoph Hellwig , "Kirill A . Shutemov" On Wed, 8 Nov 2017, Christoph Hellwig wrote: > On Wed, Nov 08, 2017 at 07:33:09AM -0500, Mikulas Patocka wrote: > > We could use the function clwb() (or arch-independent wrapper dax_flush()) > > - that uses the clflushopt instruction on Broadwell or clwb on Skylake - > > but it is very slow, write performance on Broadwell is only 350MB/s. > > > > So in practice I use the movnti instruction that bypasses cache. The > > write-combining buffer is flushed with sfence. > > And what do you do for an architecture with virtuall indexed caches? Persistent memory is not supported on such architectures - it is only supported on x86-64 and arm64. Mikulas -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org